A Look Inside And Component Analysis
Our main tools for disassembling PSUs are a Thermaltronics soldering and rework station and a Hakko 808 desoldering gun.
|Transient Filter||4x Y caps, 4x X caps, 2x CM chokes, 1x MOV, 1x CM02X|
|Inrush Protection||2x NTC Thermistor, 2x Relays|
|Bridge Rectifier(s)||1x LL15XB60 (600V, 15A @ 124°C)|
|APFC MOSFETs||3x Infineon SPW60R099C6 (650V, 24A @ 100°C, 0.099Ohm)|
|APFC Boost Diode||1x STTH3006DPI (600V, 30A @ 150°C)|
|Hold-up Cap(s)||4x Matsushita (Panasonic) (420V, 270uF each - 1080uF combined, 105°C)|
|Main Switchers||4x Infineon IPP60R160C6 (650V, 15A @ 100°C, 0.16Ohm)|
|APFC Controller||Champion CM6500 - CM03X|
|Switching Controller||Champion CM6901|
|Topology||Primary side: Full-Bridge & LLC Resonant Converter Secondary side: Syncronous Rectification & DC-DC converters|
|+12V MOSFETs||16x International Rectifier IRFH7004TRPBF (40V, 164A @ 100°C, 1.4mOhm)|
|5V & 3.3V||DC-DC Converters: 2x MOSFETs 2x APW7073 PWM Controllers|
|Filtering Capacitors||Electrolytics: Nippon Chemi-Con (105°C, KZE, KZH), Rubycom (105°C), Taicon (105°C), Suncon (105°C) Polymers: Teapo (2000h @ 105°C, CG)|
|Supervisor IC||SITI PS223 (OVP, UVP, OCP, SCP, OTP )|
|Fan Model||Young Lin Tech Double Ball-Bearing Fan DFB132512H (135mm, 12V, 3W, 2500RPM)|
|Rectifying Diode||1x SBL10SL60FCTH|
|Standby PWM Controller||STR-A6062H (15W @ 230VAC, 13W @ Universal)|
The ST1500-GS is made by Enhance Electronics and the platform is definitely a high-end unit. On the primary side a full-bridge topology is used along with an LLC resonant converter; on the secondary side both VRMs are installed on the modular PCB for decreased energy loss, while the MOSFETs that regulate the +12V rail are installed on the solder side of the mainboard. The PCB has small dimensions and the design is clean. In addition, although the APFC heat sink is large, the heat sink that holds the primary switchers is small; on the secondary side there is no heat sink, since the chassis handles the cooling of the +12V FETs.
The first part of the EMI filter is on the AC receptacle and consists of two Y and two X caps. The same filter continues on the main PCB with two X and two Y caps, two CM chokes and an MOV. There is also a CM02X on the solder side of the main PCB. This IC increases efficiency by blocking the flow of current through the discharge resistor of the X cap when voltage is connected and automatically allows current flow for the X cap to be discharged once the AC is disconnected. What made quite an impression on us was that we found two NTC thermistors for protection against large inrush currents, along with two relays. Apparently, SilverStone and Enhance take inrush current protection very seriously, outfitting this PSU with four APFC caps.
The pair of bridge rectifiers is provided by Shindengen. Their model number is LL15XB60 (600V, 15A @ 124 degrees Celsius). Combined, they can handle up to 30A of current, so they will easily handle the needs of this PSU. In the APFC converter three Infineon SPW60R099C6 (650V, 24A @ 100 C, 0.099Ohm) FETs are used along with a single STTH3006DPI (600V, 30A @ 150 C) boost diode. The bulk caps are provided by Matsushita/Panasonic (420V, 270uF, 105 C) and their combined capacity is 1080uF, which looks low for this PSU. Finally, the APFC controller is a Champion CM6500, and it is installed on a small daughterboard right next to the APFC's heat sink. A CM03X Green PFC controller is installed on the same board as the CM6500.
Four Infineon IPP60R160C6 (650V, 15A @ 100 C, 0.16Ohm) FETs are the main switchers and are arranged in a full-bridge topology, while an LLC resonant converter decreases energy loss on the switching FETs. The primary transformer has compact dimensions for a 1.5 kW unit and on the two heat sinks that reside next to it are two thermistors, providing data to the OTP (Over Temperature Protection) and fan control circuits. Finally, the electrolytic caps on the secondary side are rated at 105 C and are provided mostly by Chemi-Con. We also spotted some Rubycon caps along with a single Taicon cap. Besides electrolytic caps, Enhance used enough Teapo polymers.
An amazing number of International Rectifier FETs regulate the +12V rail with all 16 of them installed on the solder side of the main PCB. Their model number is IRFH7004TRPBF (40V, 164A @ 100°C, 1.4mOhm), and Enhance is clearly using this many of them in an effort to increase efficiency, since the more FETs, the fewer amps each one of them has to handle. In addition, less energy loss on these FETs leads to a lower thermal load, allowing for a more relaxed fan profile. The minor rails are generated by two VRMs (Voltage Regulation Modules), which are installed on the modular PCB. Each VRM uses an APW7073 PWM controller along with a single FET, which we couldn't recognize due to the partially erased markings.
On the front side of the modular PCB several Teapo polymer caps filter the minor rails while four small Suncon electrolytic caps further suppress ripple. With the modular PCB exposed, we had the chance to take a better look at the small four-pin connector, which is for the +12V, 5V and 3.3V sense wires. The PSU's PWM/FM controller receives load-regulation feedback through this connector in order to adjust the DC output rails accordingly. On the back side of the modular PCB, the traces are enhanced and in some cases shorted together with a rather sloppy method, by soldering copper wires directly on them. Finally, on the front of the modular PCB, we found the LLC resonant controller (Champion CM6901) and the protections IC, a SITI PS223.
Soldering quality on the main PCB in most areas is very good. At a one spot, however, Enhance decided to increase the conductivity of the traces by soldering the copper wires, with ugly results. Despite the unappealing look, we are reasonably certain that this significantly improved the electrical conductivity. However, in the next revision of this platform, Enhance should make the necessary changes in the design, to avoid using this sloppy method.
The cooling fan is provided by Young Lin Tech; its model number is DFB132512H (135mm, 12V, 3W, 2500 RPM). It uses a double ball-bearing for increased life, and although there is no semi-passive mode at light and medium loads, the fan is fairly quiet considering it cools down a 1500 W PSU, which spins at very low speeds when the thermal load isn't high.